Housing guard and abrasive stream control unit for rotatable abrasive throwing assemblies



Oct. 11, 1966 FAHRNEY 3,277,608

HOUSING GUARD AND ABRASIVE STREAM CONTROL UNIT FOR ROTATABLE ABRASIVE THROWING ASSEMBLIES Filed Sept. 4, 1963 INVENTOR Ma/x/iueZL EFaJI W259 ATTORNEYS United States Patent 3,277,608 HOUSING GUARD AND ABRASlVE STREAM CONTROL UNIT FOR ROTATABLE ABRA- SIVE THROWIN G ASSEMBLHES Maxwell E. Fahrney, Hagerstown, Md, assignor to The Pangborn Corporation, Hagerstown, Md, a corporation of Delaware Filed Sept. 4, 1963, Ser. No. 306,462 3 Claims. (Cl. 519) The present invention relates to a housing guard which is positioned around an abrasive blasting wheel assembly supported within a housing, which guard also controls the width of the abrasive stream as it is discharged from the blasting wheel assembly and the surrounding housing.

In many instances it is important that the length of the emitted abrasive stream be limited to certain lengths for exact coverage. For instance, in some cases only a portion of a work article will be blasted for one reason or another.

In the past, the type of blast stream control disclosed herein has not been possible since the materials from which the housing and other components of the rotatable blast wheel assembly were made were not very resistant to erosion from both direct and ricocheted blast of the abrasive being emitted at great speeds by the rotatable blast wheel assembly. In other words, the metals used could not be made sufiiciently hard to resist erosion caused by abrasive action.

It is therefore one object of the present invention to provide a new and novel abrasive blasting assembly of the rotatable wheel type wherein the abrasive stream emitted from the blast wheel can be exactly controlled according to its length.

Another object of the present invention is to provide a novel and improved rotatable blast wheel assembly wherein the lengthwise spread or path of the abrasive being emitted from the blasting wheel assembly is controlled by a suitable guard or wear plate which extends substantially around the wheel.

Other objects and advantages of the invention will become more apparent from a study of the following description and drawing wherein:

FIGURE 1 is a side view of the rotatable blast Wheel assembly with the side plate of the housing removed to show the inner workings of the assembly; and

FIGURE 2 is a fragmentary view of a modified form of this invention.

Referring now to the drawing, there is shown an overall housing 1 which supports or houses a rotatable abrasive blast wheel 3 which carries radially-extending vanes 5 which propel abrasive media. The media is received by the blades or vanes 5 through an opening 7 in cage 9 to which abrasive media is supplied by a rotatable impeller 11. The impeller 11 receives the media from a feed spout member supported adjacent a side wall of the housing 1 and extending therethrough to connect with impeller 11. The wheel 3 and impeller 11 are driven from the same shaft by an electric motor or other impeller source, not shown.

Encircling the rotatable wheel assembly is a circular guard or wear unit 13 supported by movable guard positioning and supporting shafts 14, which also extend through the end walls of the housing 1. The guard 13 extends substantially around the wheel 3 and is open at the bottom thereof as shown in the drawing. From the free ends of the circular guard, abrasive limiting legs 15 and 17 extend downwardly at angles. The depending guide bafiies or legs 15 and 17 extend downwardly through an opening 19 in the main housing 1.

3,277,608 Patented 0st. 11, 1966 With the above arrangement the only escape for the abrasive particles picked up and propelled by the wheel 3 from the housing is through the area defined by the inner surfaces of the legs 15 and 17 extending through housing opening 19. With this arrangement the lengthwise pattern of the abrasive stream or blast emitted from the vanes 5 of the wheel 3 is accurately and positively controlled. The length of the blast pattern can be changed or varied merely by changing the angles at which the legs 15 and 17 depend from the ends of circular guard or housing 13 extending around the wheel 3.

The legs 15 and 17 can either be integral with the housing or separate attached legs as shown in FIGURE 2.

The circular guard 13 including legs 15 and 17 are formed preferably of a steel alloy metal including the following Weight percentage composition:

Carbon 3.15 to 3.35. Manganese .60 to .90. Silicon .40 to .60. Chrome 16.00 to 18.00. Molybdenum 3.00 to 3.50. Phosphorus .05 max.

Of course other metals having the degree of hardness and resistance to abrasive media as that described above may also be used.

Obviously many modifications and variations of the present invention are possible in the light of the above reachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A rotatable abrasive blasting wheel assembly comprising a rotatable wheel, abrasive propelling vanes mounted on one face of said Wheel and extending radially thereof, means supported by the wheel for providing supply abrasive media to the vanes, a cylindrical guard housing encircling the rotatable wheel over an arc substantially greater than a semicircle and having an opening through which abrasive is propelled by the wheel, legs extending outwardly from each side of the opening in said guard housing, a main housing enclosing the guard housing, said main housing having a bottom, an opening in said bottom of said main housing, said legs being divergent and extending through said opening in said bottom of said main housing and being positioned so as to limit the size of the pattern of abrasive media propelled by said vanes, and each of said legs being at an angle substantially less than to a tangent to the cylindrical guard housing at the juncture of each leg and the guard housing.

2. The assembly of claim 1 wherein the legs of the guard housing are an inherent part of the guard housing.

3. The assembly of claim 1 wherein the legs are separate and connected to the guard housing.

References Cited by the Examiner UNITED STATES PATENTS 859,863 7/1907 Young et al 51-9 2,108,005 2/ 1938 Keefer 51-9 2,204,633 6/ 1940 Turnbull 51-9 2,355,726 8/ 1944 Harder et al 51-9 X 2,376,639 5/ 1945 Unger 51-9 2,909,870 10/1959 Barnes 51-9 FOREIGN PATENTS 696,005 8/ 1953 Great Britain.

LESTER M. SWINGLE, Primary Examiner. 

1. A ROTATABLE ABRASIVE BLASTING WHEEL ASSEMBLY COMPRISING A ROTATABLE WHEEL, ABRASIVE PROPELLING VANES MOUNTED ON ONE FACE OF SAID WHEEL AND EXTENDING RADIALLY THEREOF, MEANS SUPPORTED BY THE WHEEL FOR PROVIDING SUPPLY ABRASIVE MEDIA TO THE VANES, A CYLINDRICAL GUARD HOUSING ENCIRCLING THE ROTATABLE WHEEL OVER AN ARC SUBSTANTIALLY GREATER THAN A SEMICIRCLE AND HAVING AN OPENING THROUGH WHICH ABRASIVE IS PROPELLED BY THE WHEEL, LEGS EXTENDING OUTWARDLY FROM EACH SIDE OF THE OPENING IN SAID GUARD HOUSING, A MAIN HOUSING ENCLOSING THE GUARD HOUSING, SAID MAIN HOUSING HAVING A BOTTOM, AN OPENING IN SAID BOTTOM OF SAID MAIN HOUSING, SAID LEGS BEING DIVERGENT AND EXTENDING THROUGH SAID OPENING IN SAID BOTTOM OF SAID MAIN HOUSING AND BEING POSITIONED SO AS TO LIMIT THE SIZE OF THE PATTERN OF ABRASIVE MEDIA PROPELLED BY SAID VANES, AND EACH OF SAID LEGS BEING AT AN ANGLE SUBSTANTIALLY LESS THAN 180* TO A TANGENT TO THE CYLINDRICAL GUARD HOUSING AT THE JUNCTURE OF EACH LEG AND THE GUARD HOUDING 